>Using the Boyle's machine I crank up 2 lpm oxygen and 6 lpm
> nitrous oxide to produce a 75% nitrous mixture
What circuit are you using off the Boyles machine? The flow rate above is an
insufficient flow rate to prevent rebreathing with many circuits. Most
anaesthetic machines I encounter come with a Bain coaxial system (mapleson
D) system which should have at least twice the minute volume flow rate to
prevent rebreathing (Aitkenhead recommends at least 12L/min in the average
adult). I have also used the anaesthetic machine in this way but at higher
total flow rates.
That is unless you are keen on your patient taking big breaths from their
rising CO2 (No I am not serious!). Or you could use a different delivery
system which requires a lower gas flow.
You can output the Boyles machine through a mask with a resevoir at the same
flow rate but then the actual FiN2O will be reduced and you end up not
giving the 75% N2O you think you are.
Simon
Simon Carley
SpR in Emergency Medicine
Manchester Royal Infirmary
England
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Evidence based Emergency Medicine
http://www.bestbets.org
----- Original Message -----
From: Adrian Fogarty <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, December 12, 2000 3:39 AM
Subject: Re: post-reduction sedation / monitoring
> ----- Original Message -----
> From: Gautam
> > I prefer to spare as much opiate as
> > possible by using a cocktail of entonox, ketorolac and just a sniff of
> > midazolam. Once XRayed, top up the midazolam, turn up the nitrous oxide
> > and reduce.
>
> Yes Goat, I forgot to mention entonox. Right now I'm just back from my
> graveyard shift - the latter refers to the ungodly hour, not to the
clinical
> outcomes I hasten to add - and I've just done two shoulder reductions
purely
> under entonox. Using the Boyle's machine I crank up 2 lpm oxygen and 6 lpm
> nitrous oxide to produce a 75% nitrous mixture. It produces a dissociated
> state within minutes, and is perfectly adequate for an (accelerated)
> Kocher's technique. Very rapid recovery and no (electronic) monitoring is
> required or i.v. access. On each case the patient was mobile, not just
> awake, but walking out of the treatment room within 5 minutes of the start
> of the procedure! (There was no time or space to do all the morph and
midaz
> palaver so this technique worked nicely.)
>
> It's been such a crap night otherwise, I just felt I had to tell you that!
>
> Adrian Fogarty
>
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